阅读说明：本技术 一种双点采样非甲烷总烃在线监测设备及检测方法 (Double-point sampling non-methane total hydrocarbon online monitoring equipment and detection method ) 是由 黄金城 谢兆明 顾潮春 吴琼水 于 2020-06-15 设计创作，主要内容包括：本发明属于气体检测技术领域,涉及一种双点采样非甲烷总烃在线监测设备及检测方法。主要包括两个样气通道,一个十通阀、一个十二通阀、三个电磁阀、四个定量环、两路载气,已及在载气通道上的一根甲烷柱和一根总烃柱、三通汇流板、氢火焰离子化检测器,通过十通阀、十二通阀及电磁阀的通道切换形成以下模式：样气1流路为采集取样模式,样气2流路为分析检测模式和反吹模式；样气1流路为分析检测模式和反吹模式,样气2流路为采集取样模式。本发明可以实现两个采样点的非甲烷总烃在同一台仪表上、使用单个检测器检测,节约材料成本；流程设计简洁、操作简单。(The invention belongs to the technical field of gas detection, and relates to double-point sampling non-methane total hydrocarbon online monitoring equipment and a detection method. The system mainly comprises two sample gas channels, a ten-way valve, a twelve-way valve, three electromagnetic valves, four quantitative rings, two paths of carrier gases, a methane column, a total hydrocarbon column, a three-way confluence plate and a hydrogen flame ionization detector, wherein the following modes are formed by switching the channels of the ten-way valve, the twelve-way valve and the electromagnetic valves: the flow path of the sample gas 1 is in a sampling mode, and the flow path of the sample gas 2 is in an analysis and detection mode and a back flushing mode; the flow path of the sample gas 1 is in an analysis and detection mode and a back flushing mode, and the flow path of the sample gas 2 is in an acquisition and sampling mode. The invention can realize that the non-methane total hydrocarbons of two sampling points are detected on the same instrument by using a single detector, thereby saving the material cost; the process design is simple and the operation is simple.)

1. A double-point sampling non-methane total hydrocarbon on-line monitoring device comprises two sample gas channels, a ten-way valve, a twelve-way valve, three electromagnetic valves, four quantitative rings, two paths of carrier gases, a methane column and a total hydrocarbon column on the carrier gas channel, a three-way confluence plate and a hydrogen flame ionization detector, and is characterized in that the following modes are formed by switching the channels of the ten-way valve, the twelve-way valve and the electromagnetic valves: every way sample gas of two way sample gases accomplishes the sample collection respectively through two ration rings, and the carrier gas carries the sample gas in the ration ring in proper order and gets into methane column and total hydrocarbon column and separate, and the sample gas after the separation accomplishes the analysis and detection to total hydrocarbon and methane through hydrogen flame ionization detector, specifically includes: the flow path of the sample gas 1 is in a sampling mode, and the flow path of the sample gas 2 is in an analysis and detection mode and a back flushing mode; the sample gas 1 flow path is in an analysis and detection mode and a back flushing mode, and the sample gas 2 flow path is in an acquisition and sampling mode, and the method specifically comprises the following steps:

the sample gas 1 sequentially passes through the sample gas channel of the ten-way valve and the quantitative ring 1, and forms a sampling mode for collecting the sample gas 1 through the sample gas channel of the twelve-way valve and the quantitative ring 2; the carrier gas 1 carries the sample gas 2 in the quantitative ring through the quantitative ring 3 and the carrier gas 2 through the quantitative ring 4 to enter a methane column and a total hydrocarbon column for sample gas separation, and the separated sample gas enters a hydrogen flame ionization detector after passing through a three-way confluence plate to form an analysis detection mode;

after the sample gas 2 is detected, the electromagnetic valve 1 and the electromagnetic valve 2 are switched simultaneously, the carrier gas 1 carries out back flushing on the methane column, and non-methane substances in the methane column are blown back out of the methane column to form a back flushing mode;

after back flushing, simultaneously switching the ten-way valve, the twelve-way valve, the electromagnetic valve 1, the electromagnetic valve 2 and the electromagnetic valve 3 to enable the sample gas 2 to form a sampling mode through the quantitative ring 3 and the quantitative ring 4; the carrier gas 1 carries the sample gas 1 in the quantitative ring through the quantitative ring 1 and the carrier gas 2 through the quantitative ring 2 to enter a methane column and a total hydrocarbon column for sample gas separation, and the separated sample gas enters a hydrogen flame ionization detector after passing through a three-way confluence plate to form analysis detection mode detection;

after the sample gas 2 is detected, the electromagnetic valve 1 and the electromagnetic valve 2 are switched simultaneously, the carrier gas 1 carries out back flushing on the methane column, and non-methane substances in the methane column are blown back out of the methane column to form a back flushing mode.

2. The device for on-line monitoring of non-methane total hydrocarbons based on double-point sampling of claim 1, wherein the ten-way valve and the twelve-way valve are diaphragm valves, electric rotor valves or pneumatic rotor valves.

3. The on-line monitoring equipment for non-methane total hydrocarbons based on double-point sampling of claim 1 or 2, wherein the ten-way valve and the twelve-way valve have two states of initial state and load state.

4. The on-line monitoring equipment for the non-methane total hydrocarbons based on the double-point sampling of the claim 1 is characterized in that the three electromagnetic valves are two-position three-way valves.

5. The on-line monitoring equipment for the non-methane total hydrocarbons based on the double-point sampling of the claim 4, wherein two of the three two-position three-way electromagnetic valves are used for back flushing the methane column.

6. The on-line monitoring equipment for non-methane total hydrocarbons based on double-point sampling according to claim 4, wherein two of the three two-position three-way solenoid valves are high-temperature solenoid valves.

7. The on-line monitoring equipment for non-methane total hydrocarbons based on double-point sampling according to claim 1, wherein the capacities of the four quantitative rings are determined according to the detected substances, and preferably the capacities of the four quantitative rings are all 2 mL.

8. The on-line monitoring equipment for non-methane total hydrocarbons based on double-point sampling of claim 1, wherein the sample gas 1 and the sample gas 2 are sample gases at different sampling points respectively.

9. The apparatus of claim 1, wherein one of the two carrier gases is used to carry the sample gas to the monitoring apparatus and the methane blowback column.

10. A method for detecting the double-point sampling non-methane total hydrocarbon on-line monitoring device according to any one of the claims 1 to 9, which is characterized by comprising the following steps:

sampling at sampling point 1, analyzing at sampling point 2: the ten-way valve and the twelve-way valve are in initial states, the electromagnetic valve 1, the electromagnetic valve 2 and the electromagnetic valve 3 are opened, the sample gas in the sampling point 1 flows through the quantitative ring 1 and the quantitative ring 2 for sampling, and the sample gas in the quantitative ring 3 and the quantitative ring 4 enters the chromatographic column and is analyzed by the detector;

sampling at a sampling point 1, and carrying out back flushing on a methane column: the ten-way valve and the twelve-way valve are in initial states, the electromagnetic valve 1 and the electromagnetic valve 2 are closed, the electromagnetic valve 3 is opened, the sampling point 1 samples through the quantitative ring 1 and the quantitative ring 2, and the carrier gas 1 backflushs the methane column;

sample 1 analysis, sample 2 sampling: the ten-way valve and the twelve-way valve are in a load state, the electromagnetic valve 1 and the electromagnetic valve 2 are opened, the electromagnetic valve 3 is closed, the sample gas in the quantitative ring 1 and the quantitative ring 2 enters the chromatographic column and is analyzed by the detector, and the sample gas in the sampling point 2 flows through the quantitative ring 3 and the quantitative ring 4 for sampling;

back flushing of a methane column and sampling of a sampling point 2: the ten-way valve and the twelve-way valve are in a load state, the electromagnetic valve 1, the electromagnetic valve 2 and the electromagnetic valve 3 are closed, the carrier gas 1 reversely blows the methane column, and the sampling point 2 samples the sample gas flow through the quantitative ring 3 and the quantitative ring 4;

when the process is run for the first time, the numerical value is recorded from the second group of loops.

Technical Field

The invention belongs to the technical field of gas detection, and particularly relates to double-point sampling non-methane total hydrocarbon online monitoring equipment and a detection method.

Background

According to the national standard HJ 1013 and 2018 technical requirements and detection method for a continuous monitoring system for non-methane total hydrocarbons in exhaust gas of fixed pollution sources, the non-methane total hydrocarbons (NMHC) refers to the sum of other gaseous organic compounds after methane is subtracted from the total hydrocarbons. NMHC has great photochemical activity, is a precursor for forming photochemical smog, and when the content of NMHC in the atmosphere exceeds a certain concentration, the NMHC can directly harm human health, and can also generate photochemical smog under certain illumination conditions, so that harm is caused to people and the environment.

NMHC has wide source and complex components. At present, a plurality of methods for monitoring NMHC in atmosphere and industrial waste gas exist, and the mainstream method is gas chromatography. In the gas chromatography for NMHC detection, gas paths are often switched by using a multi-way valve to detect total hydrocarbons and methane, and the NMHC value is calculated. However, the detection devices and the detection methods can only realize NMHC online detection of a single detection port. However, for modern enterprises, each enterprise has more than one sampling point and detection port. One detection port needs one detection instrument, and cost and human resource waste are caused for enterprises. Meanwhile, the non-methane total hydrocarbon on-line monitoring equipment with double-point sampling can compare the data of two sampling points more visually.

The NMHC detection device and the NMHC detection method have the problem that double-point or multi-point sampling detection cannot be achieved. There is a need for an on-line monitoring device and a detection method for non-methane total hydrocarbons, which provide double-point detection to solve the problems of the prior art.

Disclosure of Invention

In order to solve the defects in the prior art, the invention provides double-point sampling non-methane total hydrocarbon online monitoring equipment and a detection method. The problem of can't realize among the prior art that single instrument or single detector detect two detection mouths is solved, practice thrift the cost.

The invention provides double-point sampling non-methane total hydrocarbon on-line monitoring equipment, which adopts the following main technical scheme: the device mainly comprises two sample gas channels, a ten-way valve, a twelve-way valve, three electromagnetic valves, four quantitative rings, two paths of carrier gases, a methane column, a total hydrocarbon column, a three-way confluence plate and a hydrogen flame ionization detector, wherein the following modes are formed by switching the channels of the ten-way valve, the twelve-way valve and the electromagnetic valves: every way sample gas of two way sample gases accomplishes the sample collection respectively through two ration rings, and the carrier gas carries the sample gas in the ration ring in proper order and gets into methane column and total hydrocarbon column and separate, and the sample gas after the separation accomplishes the analysis and detection to total hydrocarbon and methane through hydrogen flame ionization detector, specifically includes: the flow path of the sample gas 1 is in a sampling mode, and the flow path of the sample gas 2 is in an analysis and detection mode and a back flushing mode; the sample gas 1 flow path is in an analysis and detection mode and a back flushing mode, and the sample gas 2 flow path is in an acquisition and sampling mode, and the method specifically comprises the following steps:

the sample gas 1 sequentially passes through the sample gas channel of the ten-way valve and the quantitative ring 1, and forms a sampling mode for collecting the sample gas 1 through the sample gas channel of the twelve-way valve and the quantitative ring 2; the carrier gas 1 carries the sample gas 2 in the quantitative ring through the quantitative ring 3 and the carrier gas 2 through the quantitative ring 4 to enter a methane column and a total hydrocarbon column for sample gas separation, and the separated sample gas enters a hydrogen flame ionization detector after passing through a three-way confluence plate to form an analysis detection mode;

after the sample gas 2 is detected, the electromagnetic valve 1 and the electromagnetic valve 2 are switched simultaneously, the carrier gas 1 carries out back flushing on the methane column, and non-methane substances in the methane column are blown back out of the methane column to form a back flushing mode;

after back flushing, simultaneously switching the ten-way valve, the twelve-way valve, the electromagnetic valve 1, the electromagnetic valve 2 and the electromagnetic valve 3 to enable the sample gas 2 to form a sampling mode through the quantitative ring 3 and the quantitative ring 4; the carrier gas 1 carries the sample gas 1 in the quantitative ring through the quantitative ring 1 and the carrier gas 2 through the quantitative ring 2 to enter a methane column and a total hydrocarbon column for sample gas separation, and the separated sample gas enters a hydrogen flame ionization detector after passing through a three-way confluence plate to form analysis detection mode detection;

after the sample gas 2 is detected, the electromagnetic valve 1 and the electromagnetic valve 2 are switched simultaneously, the carrier gas 1 carries out back flushing on the methane column, and non-methane substances in the methane column are blown back out of the methane column to form a back flushing mode.

Preferably, the ten-way valve and the twelve-way valve are diaphragm valves, electric rotor valves or pneumatic rotor valves.

Preferably, the ten-way valve and the twelve-way valve have two states, an initial state and a load state.

Preferably, the three electromagnetic valves are two-position three-way valves.

Preferably, two of the three two-position three-way electromagnetic valves are used for back flushing the methane column.

Preferably, two of the three two-position three-way solenoid valves are high-temperature solenoid valves.

Preferably, the capacity of the four quantification loops is determined according to the substance to be detected, and preferably, the capacity of each of the four quantification loops is 2 mL.

Preferably, the sample gas 1 and the sample gas 2 are respectively sampled at different points.

Preferably, one of the two carrier gases is used for loading the sample gas into the monitoring equipment and the back-flushing methane column at the same time.

The invention also provides a detection method of the double-point sampling non-methane total hydrocarbon on-line monitoring equipment, which mainly comprises the following steps:

(1) sampling at sampling point 1, analyzing at sampling point 2: the ten-way valve and the twelve-way valve are in initial states, the electromagnetic valve 1, the electromagnetic valve 2 and the electromagnetic valve 3 are opened, the sample gas in the sampling point 1 flows through the quantitative ring 1 and the quantitative ring 2 for sampling, and the sample gas in the quantitative ring 3 and the quantitative ring 4 enters the chromatographic column and is analyzed by the detector;

(2) sampling at a sampling point 1, and carrying out back flushing on a methane column: the ten-way valve and the twelve-way valve are in initial states, the electromagnetic valve 1 and the electromagnetic valve 2 are closed, the electromagnetic valve 3 is opened, the sampling point 1 samples through the quantitative ring 1 and the quantitative ring 2, and the carrier gas 1 backflushs the methane column;

(3) sample 1 analysis, sample 2 sampling: the ten-way valve and the twelve-way valve are in a load state, the electromagnetic valve 1 and the electromagnetic valve 2 are opened, the electromagnetic valve 3 is closed, the sample gas in the quantitative ring 1 and the quantitative ring 2 enters the chromatographic column and is analyzed by the detector, and the sample gas in the sampling point 2 flows through the quantitative ring 3 and the quantitative ring 4 for sampling;

(4) back flushing of a methane column and sampling of a sampling point 2: the ten-way valve and the twelve-way valve are in a load state, the electromagnetic valve 1, the electromagnetic valve 2 and the electromagnetic valve 3 are closed, the carrier gas 1 reversely blows the methane column, and the sampling point 2 samples the sample gas flow through the quantitative ring 3 and the quantitative ring 4;

when the process is run for the first time, the numerical value is recorded from the second group of loops.

In the present invention, the carrier gas may be high purity air or high purity nitrogen gas.

The hydrogen and the combustion-supporting air of the hydrogen flame ionization detector can be generated by a hydrogen-air integrated machine or directly adopt the hydrogen and the air of a high-purity steel cylinder.

Compared with the prior art, the invention has the beneficial effects that:

1. the double-point sampling non-methane total hydrocarbon on-line monitoring equipment and the detection method provided by the invention can realize that the non-methane total hydrocarbons at two sampling points are detected on the same instrument by using a single detector, thereby saving the material cost;

2. the double-point sampling non-methane total hydrocarbon on-line monitoring equipment and the monitoring method provided by the invention have the advantages of concise flow design and simple operation.

Drawings

FIG. 1 is a flow chart of the analysis state of sample gas at sample point 1 and sample point 2 in the double-point sampling non-methane total hydrocarbon on-line detection method in the embodiment of the invention.

FIG. 2 is a flow chart of sampling point 1 sampling and methane column blowback states of the double-point sampling non-methane total hydrocarbon online detection method in the embodiment of the invention.

Fig. 3 is a flow chart of sampling point 1 analysis and sampling point 2 sampling states of the double-point sampling non-methane total hydrocarbon online detection method in the embodiment of the invention.

FIG. 4 is a flow chart of sampling point 2 sampling and methane column blowback status of the double-point sampling non-methane total hydrocarbon on-line detection method in the embodiment of the present invention.

Detailed Description

The present invention will be described in detail below with reference to examples and the accompanying drawings.